Casimir I of Poland

Casimir I the Restorer of Poland (1016-1058) was the king of Poland from 1034 until 1058. He was responsible for the reunification of the Duchy of Poland, Masovia, Silesia, and Pomerania under Polish rule, but was never recognized as King of Poland.

Biography
Casimir was the son of Mieszko II of Poland, and was born in a period of disunity. Masovia, Poland, Silesia, and Pomerania separated into four duchies, so Casimir had to fight to regain his lands. From 1034 onwards, Casimir allied with Yaroslav I of Rus and Henry III of Germany and reconquered all of his lands. He gave Henry control of Silesia, which became a part of the Kingdom of Bohemia, and Casimir seized Masovia in 1047.

After re-unifying Poland, Casimir started expanding his lands. He invaded the Kingdom of Hungary to the south in 1055 and defeated the army of Andrew I of Hungary at the Battle of Presov in Slovakia. Both rulers were wounded and Casimir barely survived, so he decided to make peace with his foe. He reset the Polish capital to Krakow and died in the city. He was succeeded by Boleslaw II of Poland.